We are going to embed this calculator into a dashboard of online project management application Easy Redmine. As you can see above this dashboard renders our 4 variables from its database. The dashboard is classical HTML page so our embed is very easy - we just use the standard embed code.

The magic is that as a site renders, Calculoid loads data from the site into its own variables and provides on-the-fly calculations above them

This fetch of statically loaded HTML data is done by simple javascript which goes with embed script itself. JS looks as below and its download is here.

All you need to do in order to create your own custom connection JS is to inspect a site above which you are going to make similar on the fly calculations for as precise HTML element IDs of your variables as possible.

And afterward, connect data of these HTML elements to unique variables of your calculator.

As a result, Calculoid Calculator provides real-time business calculations above any HTML data.